高度组织的文石介晶棒：一种普遍的三维取向连接及其生物矿化意义

Highly organized aragonite mesorods were synthesized at low temperatures in a broad range of pH values and in absence of any bio- or organic- macromolecules. The organized mesorods were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scan electron microscope (FESEM), transmission electron microscope (TEM), and selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDX) techniques. FESEM results reveal that the aragonite mesorods are not only assembled with aragonite microrods by end-to-end, and side-to-side, but also partially fused one another, forming flat faceted surfaces. TEM and SAED analyses confirm that the organized mesorods have the same crystallographic symmetry as the single-crystalline aragonite, indicating that the self-assembly process is favorable energetically. Similar assembly process also occurs for mineral strontianite or witherite of aragonite group. The driving force for the self-assembly process may originate from the inherent anisotropic dipole-dipole interactions between the assembled units. As a result, a general 3D oriented attachment process may orchestrate the mesorods self-assembly into quasi-single crystalline microrods, and such mineralization mechanism can generally occur in biomineralization. It appears that the biological genetic and crystallochemical factors may work synergically in biomineralization.